Startups are well-known for being go fast, release and iterate. Having quality engineers at Sumo Logic is a big part of doing that well enough that customers want our solution, but like many other young tech companies open source libraries and tools are also a key element in our ability to deliver. As a recent hire into the User Interface development team I was excited to see just which open source software goes into our cloud log management solution. The list is extensive, because so many of our peers are making great stuff available, but a quick look just at the front end codebase shows: jQuery: The big daddy, jQuery is used by millions of web applications and websites to add dynamic behavior and content to otherwise plain pages. Backbone: A lean, subtly powerful framework for building expressive client-side apps, Backbone provides a core set of MV* classes and a foundation for many community-developed extensions. Sass/Compass: Think “programmable CSS” and you’re capturing the essence of Sass while big brother Compass adds an extensive set of reusable cross-browser CSS patterns as well as several handy utilities. D3: A library for manipulating documents based on data, we use D3 to drive many of the beautiful interactive charts that enable our customers to understand the huge volume of data they process in our application. Require.js: Building large applications is much easier to manage when code can be split into small, coherent chunks (files) and Require.js enables apps to do just this. Code Mirror: This versatile text editor is the basis for Sumo Logic’s powerful search query editors. jQuery Plugins: Many, the more important to us include Select2, Toaster, qTip, and jQuery’s jQuery UI. Collectively these libraries–along with their counterparts used in our service layer–make it possible for a small company to rapidly deliver the depth and quality of Sumo Logic in a cost-effective process. Instead of writing essentially boilerplate code to perform mundane tasks our team is able to create application-specific high value code. In the days before FOSS proliferated the cost per developer or per CPU for each piece of software would have been prohibitive; the economics of Silicon Valley, where two guys in a coffee shop can spin up a Pinterest or Sumo Logic, just wouldn’t have worked.